Predicting virtual acoustic source properties in a stereophonic sound-field using the coherence properties of the acoustic velocity vector field

Abstract

It is widely understood that the mutual coherence properties, including the relative phase, of the channel signals in a stereophonic sound reproduction system significantly influence a listener’s perception of the resulting virtual acoustic sources. This talk presents a quantitative model that combines wavefield coherence theory, the acoustic velocity vector, and known perceptual cues to make quantitative predictions of the perceived location and spatial spread of horizontally placed stereophonic virtual sources as a function of the mutual coherence properties of the stereo channel signals. It will be seen that a small number of parameters, including the intrinsic coherence time of the source signal, the relative phase of the channels, and perceptual averaging times, account for most of the variation in the cues that determine virtual acoustic source localization. The output of the coherence model will be compared to the results of earlier experiments, including ones investigating the “phaseyness” problem and precedence effect. Additionally, the potential of this model to account for reverberation in the listening space will be demonstrated.